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941.
N-Amido imidazolium salt was employed as a ligand in the palladium-catalyzed cross-coupling reaction of aryl halides and thiols, and showed good activity in the formation of thioether. The best combination for the coupling with aryl bromides was N-amido imidazolium salt 2 and NaHMDS, and that for the coupling with aryl iodides was N-amido imidazolium salt 1 and KOtBu. The coupling reactions were conducted in the presence of Pd(OAc)2 (1 mol %) in DMSO at 80 °C for 12 h. 相似文献
942.
Sung Wook Kang Ok Kyun Kim Bochan Seo Sung Ho Lee Fu Shi Quan Jae Ho Shin Gi-Ja Lee Hun-Kuk Park 《Analytica chimica acta》2013
In this study, we simultaneously measured nitric oxide (NO) and oxygen (O2) dynamics in the myocardium during myocardial ischemia-reperfusion (IR) utilizing sol-gel modified electrochemical NO and O2 microsensors. In addition, we attempted to clarify the correlation between NO release in the ischemic period and O2 restoration in the myocardium after reperfusion, comparing a control heart with a remote ischemic preconditioning (RIPC)-treated heart as an attractive strategy for myocardial protection. Rat hearts were randomly divided into two groups: a control group (n = 5) and an RIPC group (n = 5, with RIPC treatment). Myocardia that underwent RIPC treatment (182 ± 70 nM, p < 0.05) released more NO during the ischemic period than those of the control group (63 ± 41 nM). The restoration value of oxygen tension (pO2) in the RIPC group significantly increased and was restored to pre-ischemic levels (92.6 ± 36.8%); however, the pO2 of the control group did not increase throughout the reperfusion period (5.7 ± 7.5%, p = 0.001). Myocardial infarct size measurements revealed a significant decrease in cell death in the myocardium region of the RIPC group (41.44 ± 6.42%, p = 0.001) compared with the control group (60.05 ± 10.91%). As a result, we showed that the cardioprotective effect of RIPC could be attributed to endogenous NO production during the ischemic period, which subsequently promoted reoxygenation in post-ischemic myocardia during early reperfusion. Our results suggest that the promotion of endogenous formation during an ischemic episode might be helpful as a therapeutic strategy for protecting the myocardium from IR injury. Additionally, our NO and O2 perm-selective microsensors could be utilized to evaluate the effect of drug or treatment. 相似文献
943.
Jin Sung Park Da-Young Chang Ji-Hoi Kim Jin Hwa Jung JoonSeong Park Se-Hyuk Kim Young-Don Lee Sung-Soo Kim Haeyoung Suh-Kim 《Experimental & molecular medicine》2013,45(2):e10
Human mesenchymal stem cells (MSCs) have emerged as attractive cellular vehicles
to deliver therapeutic genes for ex-vivo therapy of diverse diseases;
this is, in part, because they have the capability to migrate into tumor or
lesion sites. Previously, we showed that MSCs could be utilized to deliver a
bacterial cytosine deaminase (CD) suicide gene to brain tumors. Here we
assessed whether transduction with a retroviral vector encoding CD gene
altered the stem cell property of MSCs. MSCs were transduced at passage 1 and
cultivated up to passage 11. We found that proliferation and differentiation
potentials, chromosomal stability and surface antigenicity of MSCs were not
altered by retroviral transduction. The results indicate that retroviral vectors
can be safely utilized for delivery of suicide genes to MSCs for
ex-vivo therapy. We also found that a single retroviral
transduction was sufficient for sustainable expression up to passage 10. The
persistent expression of the transduced gene indicates that transduced MSCs
provide a tractable and manageable approach for potential use in allogeneic
transplantation. 相似文献
944.
945.
Hongki Kim Dr. Taejoon Kang Hyoban Lee Hyunseong Ryoo Dr. Seung Min Yoo Prof. Dr. Sang Yup Lee Prof. Dr. Bongsoo Kim 《化学:亚洲杂志》2013,8(12):3010-3014
The direct transfer of single‐crystalline Au nanowires (NWs) onto Au substrates was achieved by a simple attachment and detachment process. In the presence of a lubricant, Au NWs grown vertically on a sapphire substrate were efficiently moved to an Au substrate through van der Waals interactions. We demonstrate that the transferred Au NWs on the Au substrate can act as sensitive, reproducible, and long‐term‐stable surface‐enhanced Raman scattering (SERS) sensors by detecting human α‐thrombin as well as Pb2+ and Hg2+ ions. These three biochemically and/or environmentally important analytes were successfully detected with high sensitivity and selectivity by Au NW‐SERS sensors bound by a thrombin‐binding aptamer. Furthermore, the as‐prepared sensors remained in working order after being stored under ambient conditions at room temperature for 80 days. Because Au NWs can be routinely transferred onto Au substrates and because the resultant Au NW‐SERS sensors are highly stable and provide with high sensitivity and reproducibility of detection, these sensors hold potential for practical use in biochemical sensing. 相似文献
946.
Kyeong‐Ryoon Lee Sung Heum Choi Jin‐Sook Song Hyewon Seo Yoon‐Jee Chae Hwang Eui Cho Jin Hee Ahn Sung‐Hoon Ahn Myung Ae Bae 《Biomedical chromatography : BMC》2013,27(7):846-852
In this study, we developed a method for the determination of PF‐04620110 (2‐{(1r,4r)‐4‐[4‐(4‐amino‐5‐oxo‐7,8‐dihydropyrimido[5,4‐f][1,4]oxazepin‐6(5H)‐yl)phenyl]cyclohexyl}acetic acid), a novel diacylglycerol acyltransferase 1 (DGAT‐1) inhibitor, in rat plasma and validated it using liquid chromatography–tandem mass spectrometry (LC‐MS/MS). Rat plasma samples were processed following a protein precipitation method by using acetonitrile and were then injected into an LC‐MS/MS system for quantification. PF‐04620110 and imipramine (internal standard) were separated using a Hypersil Gold C18 column, with a mixture of acetonitrile and 10 mm ammonium formate (90:10, v/v) as the mobile phase. The ion transitions monitored in positive‐ion mode [M + H]+ of multiple‐reaction monitoring were m/z 397.0 → 260.2 for PF‐04620110 and m/z 280.8 → 86.0 for imipramine. The detector response was specific and linear for PF‐04620110 at concentrations within the range 0.05–50 µg/mL and the signal‐to‐noise ratios for the samples were ≥10. The intra‐ and inter‐day precision and accuracy of the method matched the acceptance criteria for assay validation. PF‐04620110 was stable under various processing and/or handling conditions. PF‐04620110 concentrations in the rat plasma samples could be measured up to 24 h after intravenous or oral administration of PF‐04620110, suggesting that the assay is useful for pharmacokinetic studies in rats. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
947.
Tzu‐Chuan Huang Shih‐Ming Chen Yi‐Chieh Li Jen‐Ai Lee 《Biomedical chromatography : BMC》2013,27(9):1100-1106
Urinary d ‐lactate is highly correlated to diabetic nephropathy – a progressive kidney disease in renal glomeruli. In this study, we used a C3H/3e mouse model to investigate the relationship between urinary d ‐lactate and aristolochic acid nephropathy where the glomerular structure is not affected. The nephropathy was induced using intravenous injections of aristolochic acid at a dosage of 10 mg/kg per day for 5 days and was characterized biochemically and histologically. The urinary excretions of proteins, N‐acetyl‐β‐d ‐glucosaminidase and serum creatinine were determined and connected to histological conventional findings. Urinary d ‐lactate was analyzed using column‐switching high‐performance liquid chromatography with fluorescence detection. The results showed a remarkable increase of urinary markers, including of urinary proteins and N‐acetyl‐β‐d ‐glucosaminidase, and the histological examination confirmed a diagnosis of acute tubule necrosis. The ratio of d ‐lactate to creatinine in the urine of aristolochic acid‐treated mice was approximately 36 times greater than that of the mice in the control group (p < 0.05). The ratios for the two groups of mice were 311.00 ± 71.70 and 8.60 ± 1.80 µmol/mmol creatinine, respectively. These data confirm in vivo that urinary d ‐lactate reflects renal injury conditions in aristolochic acid‐treated mice and may be a marker for the assessment of nephropathy. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
948.
Dr. Sung Lan Jeon Dr. Min Kyung Chae Eun Ju Jang Dr. Chulhyun Lee 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(13):4217-4222
Iron oxide nanoparticles as contrast agents are reported to effectively improve magnetic resonance imaging of tissues and cells. In this work, cleaved iron oxide nanoparticles (CIONPs) were generated from hydrophobic FeO nanoparticles (HIONPs) by coating their surfaces with PEG‐phospholipids, oxidizing them under water, and slowly removing the residual FeO phase in phthalate buffer. The synthesized CIONPs showed good r2 values of up to 258 s?1 mM ?1. Thus, the CIONPs can be employed as vectors for drug delivery due to their unique structure with an empty inner space, which enables their use in a wide range of applications. 相似文献
949.